A simplified approach to the treatment of Duane's syndrome

INTRODUCTION

To report the results of a large series of patients undergoing treatment for Duane's syndrome.

METHODS

Patients with Duane's syndrome undergoing strabismus surgery of a horizontal muscle recession procedure, medial rectus recession for an esodeviation or lateral rectus recession for an exodeviation, in order to correct an abnormal head position (AHP) and a significant tropia in primary position were identified. Amount of recession varied with the angle of deviation in forced primary position, versions and ductions, and intraoperative forced ductions. Elimination of AHP was used as a criterion for success.

RESULTS

Fifty nine patients were treated with either unilateral or bilateral medial or lateral rectus recession. Mean follow up was 3.1 years. Ninety three percent achieved a postoperative alignment of < or =15 degrees AHP, 66% achieved < or =5 degrees AHP. Only three patients, two from the unilateral Type II group and one from the bilateral combined Types I and II group, went on to have a second procedure for a noticeable residual AHP.

CONCLUSIONS

Success (good to excellent results) of horizontal muscle recession was achieved in 93% of patients. Unilateral or bilateral horizontal rectus muscle recession offers a simple and effective surgical option for eliminating AHP and is our treatment of choice in patients with Duane's syndrome.

Surgical outcome after prism adaptation for esotropia with a distance-near disparity

INTRODUCTION

Prism adaptation for patients with esotropia and a distance-near disparity is controversial. The purpose of this study was to evaluate the surgical outcome for patients who underwent prism adaptation for esotropia with a distance-near disparity and determine whether both preoperative sensory and motor fusion are necessary to determine surgical success.

METHODS

The medical records of 65 prism-adapted patients with a distance-near disparity of 9 PD or more were reviewed. Prism responders had a fusion response to near Worth 4-dot test and a deviation with prisms of 8 PD or less of esotropia at near, and 5 PD or less of exotropia at distance, or both. The same criteria were used postoperatively to assess a successful surgical outcome. Patients were operated for the near angle or greater than the near angle.

RESULTS

Fifty-eight of 65 patients (89%) demonstrated fusion with prisms. Twenty of 65 patients (31%) had increased deviations that were greater than their original near angle (prism builders). Eleven percent (7 of 65) had no fusion. Postoperatively, 88% (51 of 58) of all fusers, 95% (18 of 19) of prism builders, and 71% (5 of 7) of nonfusers had a good surgical outcome of 8 PD or less of esotropia at near, 5 PD or less of exotropia at distance, or both.

CONCLUSIONS

Prism response for distance-near disparity esotropia is a good indicator of postoperative outcome. Responders to prism adaptation had a better surgical outcome compared with nonresponders. In particular, prism adaptation aids in detecting those patients who will benefit from larger amounts of surgical correction.

Taking a history of the patient with diplopia

The diagnosis and treatment of adult diplopia is challenging. Having a thorough and complete history of the patient can make this difficult process easier. This article describes the most important questions to ask when taking the history of a patient with diplopia and explains why a particular question is essential. Tips of what to search for in the patient's answers are also provided.

Postoperative results in inferior oblique palsy

PURPOSE

Although rare, the entity of isolated inferior oblique palsy has been discussed in past literature. The purpose of this study is to expand on the number of cases as well as the surgical options. Postoperative clinical findings, especially head-tilt measurements also are discussed.

METHODS

The charts of patients were retrospectively reviewed following surgical correction of unilateral inferior oblique palsy. Data analyzed included type of surgical correction, pre- and postoperative measurements in all fields of gaze, torsion, and sensory status.

RESULTS

Twenty-eight patients were studied. Patients were separated into groups based on the type of procedure performed. Indications for each type of procedure will be discussed. Twenty-three patients had a single surgical procedure. Of these, 16 had excellent surgical results. Five patients required reoperation with four achieving an excellent surgical result. Head-tilt testing at the last postoperative visit was positive for iatrogenic superior oblique palsy (4) and residual inferior oblique palsy (3).

CONCLUSIONS

In the largest series of unilateral inferior oblique palsy to date, the results appear to be good if the indications for the proper surgical procedure are followed. The number of cases of iatrogenic superior oblique palsy appear to be consistent with that discussed in previous literature, but not higher than the incidence of residual inferior oblique palsy. Postoperative head-tilt measurements were consistent with the deviation found in other fields of gaze.

20th annual Frank Costenbader Lecture--adult strabismus

BACKGROUND

A retrospective analysis of adults with strabismus was done to examine the potential risks and the possible benefits of surgical treatment and to describe the types of adult strabismus.

METHODS

Eight hundred ninety-two patients were analyzed. Age at time of surgery ranged from 9 years to 89 years. The average follow up was 34 months. Major types of strabismus were grouped by their original diagnoses. The group of patients with horizontal strabismus, which usually had an onset before 9, was termed the before visual maturity (BVM) group. The group of patients with paretic or restrictive strabismus usually had the onset of strabismus after age 9 and was termed the after visual maturity (AVM) group.

RESULTS

Patients with adult strabismus can gain restoration of alignment, as well as binocular function. At the last postoperative visit, 74% of the BVM group were aligned within 15 prism diopters. Not only was restoration of alignment accomplished, many of them gained some degree of sensory fusion as measured by the Worth 4-Dot (W4D) or Titmus stereoacuity. Twenty-nine percent of patients with congenital esotropia had some sensory fusion. The other subtypes in the BVM group had even higher percentages of patients with postoperative stereoacuity. In the AVM group, 92% had fusion at the last postoperative visit.

CONCLUSIONS

The outcomes of adult strabismics in our study show that certain benefits can be gained from correction of ocular alignment. Restoration of alignment, elimination of diplopia and sensory fusion are functional benefits that can be obtained through strabismus surgery in the adult patient. It is clear that adult strabismus is more than just a cosmetic problem and treatment is worthwhile.

Upper age limit for the development of amblyopia

The medical records of 64 patients between 1 and 11 years old with known onset of an amblyopia-inducing condition were retrospectively reviewed to determine the upper age limit for the development of amblyopia. Thirty seven patients (group 1) developed amblyopia and 27 patients (group 2) did not. The mean patient age at the onset of the amblyopia-inducing condition was 41.0 months (2.90 SE) for group 1 and 92.3 months (4.02 SE) for group 2. The difference was statistically significant (P = .0001). No patient developed amblyopia after 73 months of age. The duration of the amblyopia-inducing condition and the type of amblyopia-inducing condition were not significantly different between the two groups. The age of the patient when exposed to an amblyopia-inducing condition is the most important determinant for the development of amblyopia. Patients 6 years or older with a normal visual system have a low probability of developing amblyopia following the onset of an amblyopia-inducing condition.

Ocular trauma in children

1. The frequency of eye injuries in children is high. The frequency and severity of at least 90% of these injuries, however, could be prevented. 2. Toys, especially bicycles and BB guns, are a major source of eye injury. Another major cause of ocular trauma is sports-related injuries. 3. Ophthalmic professionals should emphasize the role of spectacles as a protective device for children and advise parents of the advantages of polycarbonate spectacles.

Compliance with safety glasses wear in monocular children

1. To evaluate compliance with safety glasses wear in these children, we reviewed the charts of all children (< 21 years old) treated with enucleation and followed at the University of Iowa by the Pediatric Ophthalmology Service between 1962 and 1991. 2. Fifteen of the 33 respondents reported at least one potentially serious accident in which the safety glasses had protected the good eye. 3. Compliance with safety glasses wear appears to be good in this population and may prevent injury to the remaining eye. We recommend prescribing polycarbonate safety glasses for all monocular and functionally monocular children regardless of refractive error or gender.

Compliance with safety glasses wear in monocular children

Many ophthalmologists prescribe polycarbonate "safety glasses" to protect the remaining eye of monocular patients. Others do not routinely do so when the remaining eye is emmetropic since they feel compliance is poor. To evaluate compliance with safety glasses wear in these children, we reviewed the charts of all children (< 21 years old) treated with enucleation and followed at the University of Iowa by the Pediatric Ophthalmology Service between 1962 and 1991. Safety glasses were defined as polycarbonate lenses in a frame suitable for protective wear with spherical equivalent < or = -0.75 or < or = +2.00 diopters. Fifty-six patients were followed after enucleation. Forty-six of these patients met the inclusion criteria and 33 patients were available for follow up. Eighty-five percent of patients wear safety glasses > or = 50% of their waking hours; 61% wear them > or = 80% of the time; 33% wear them 100% of their waking hours. Twenty-one of the 33 patients participate in sports. One hundred percent of the female participants and 80% to 93% of the male participants wear safety glasses, goggles, or face shields during sports. Fifteen of the 33 respondents reported at least one potentially serious accident in which the safety glasses had protected the good eye. Compliance with safety glasses wear appears to be good in this population and may prevent injury to the remaining eye.

Results of amblyopia therapy in eyes with unilateral structural abnormalities

PURPOSE

The purpose of this study is to analyze the visual results of full-time occlusion therapy in pediatric patients with monocular structural abnormalities and amblyopia.

METHODS

The authors reviewed the charts of visually immature patients with unilateral structural abnormalities and decreased visual acuity, who presented to the University of Iowa Hospitals and Clinics over a 20-year period, and underwent amblyopia therapy. The results were categorized according to the type of structural abnormality (i.e., partial media opacity, macula lesion, or optic nerve abnormality). Associated factors, including anisometropia, strabismus, age of presentation, and pupillary responses, were analyzed.

RESULTS

Fifty-one percent of the 51 patients in the study achieved a visual acuity of at least 20/80, including 72% of the patients with media opacities, 42% with macular lesions, and 21% with optic nerve anomalies. Strabismus and anisometropia occurred frequently and were not prognostically significant. Relative afferent pupillary defects did not contraindicate good results. Amblyopia recurred in 31% of patients and was successfully treated with resumption of full-time occlusion. Occlusion amblyopia occurred in only one patient and was easily reversed.

CONCLUSION

The authors recommend a trial of full-time occlusion for patients with all three types of unilateral structural abnormalities. The patients with partial media opacities have a high success rate. Despite lower success rates for the other two groups, good results are possible; no better treatment option exists.

Long-term results of adjustable suture surgery for strabismus secondary to thyroid ophthalmopathy

PURPOSE

To review the results of adjustable suture surgery in patients with strabismus secondary to thyroid ophthalmopathy to determine long-term outcome and to identify postoperative complications.

METHODS

The records of 1524 patients with thyroid ophthalmopathy were retrospectively reviewed to identify those who required treatment for strabismus in the ocular motility clinic. Treatment consisted of adjustable suture surgery, prisms, or both. Elimination of diplopia in primary and reading positions was used at the criterion for success.

RESULTS

Forty-seven patients were treated with adjustable suture surgery, with an average follow-up of 41 months. Results after 1 or more surgeries were: 47% excellent, 26% good, 19% fair, and 9% poor. Significant postoperative complications included eyelid retraction and A-pattern exodeviation. Sixteen of 18 patients with fair or poor outcomes after the initial surgery were recognized within 6 months. Postoperative changes in vertical deviation from primary position to downgaze were predictive of postoperative diplopia in downgaze. Analysis of multiple preoperative characteristics showed no statistically significant associations with outcome. Eight additional patients had adequate relief of diplopia using prisms alone, with an average follow-up of 49 months.

CONCLUSIONS

Long-term symptomatic relief of diplopia was obtained in the majority of patients using adjustable suture strabismus surgery, combined occasionally with small amounts of prism postoperatively. Prisms alone provided effective long-term relief in patients with small-to-moderate deviations.

Prism adaptation for esotropia with a distance-near disparity

A series of 64 patients who had surgery for esotropia with a distance-near disparity of at least 10 prism diopters was reviewed. Thirty-three patients were prism adapted for their distance deviation (PA distance). Thirty-one patients were prism adapted for near deviation (PA near). Both groups were divided into responders and nonresponders. In the PA distance group, 22 (67%) patients were responders. All responders had surgery for their prism-adapted angle. Postoperatively, 19 (86%) responders had fusion. Thirteen (68%) required bifocals to maintain fusion. In the PA near group, 21 (68%) patients were responders. All responders had surgery for their prism-adapted angle. Ninety-four percent of responders had fusion postoperatively. None needed bifocals for fusion postoperatively and none were overcorrected. The results show that those patients who were prism adapted for their near angle, responded with fusion, and had surgery for their full amount of esotropia at prism response obtained better postoperative fusion, without the need for a bifocal at near and without overcorrection at distance.

Anisometropic amblyopia

One hundred twenty-four patients with anisometropia of 1 diopter or greater and amblyopia were reviewed as to the type and amount of anisometropia, whether or not they had consulted with an ophthalmologist, visual acuity before and after treatment, and type of treatment. The patient population was divided into five groups according to the type of anisometropia. Eighty-two percent of all patients reached a visual acuity of 20/40 or better. Eighteen percent of all patients reached a visual acuity of 20/20. The best visual acuity obtained was not found to be related to the degree of anisometropia or the age at which treatment was begun. Patients with myopic and compound myopic astigmatism/mixed astigmatism anisometropia had poorer visual outcomes. There was a strong positive correlation between the initial visual acuity and the best visual acuity obtained (P = 0.0001).

The gradient filter test to assess amblyopia

A new technique, the gradient filter test, was developed for evaluating changes in the visual acuity of preverbal children undergoing treatment for amblyopia. The gradient filter test consists of a series of calibrated photographic fog filter and prism lenses. The combined prism-filter lenses are placed in front of the normal fixing eye. The greatest density (fogging value) filter that causes a switch in fixation from the amblyopic to the normal eye is noted. In both normal eyes of 20 nonamblyopic patients and the fellow (non-amblyopic) eyes of 20 amblyopic patients, visual acuity decreased as the density of the prism-filter lens increased. The gradient filter test accurately detected an improvement in visual acuity when compared with optotype measurements in eight patients undergoing occlusion therapy. The gradient filter test is a useful clinical tool that can assess changes in visual acuity in preverbal children who are being treated for amblyopia.